Method of and furnace for heat-treating sheet and tin-plate bars



'T'. V. ALLIS, DECD.

. n, E. e. ALLIS, ADMI-NISTRATRIX.

METHOD OF AND FURNACE FOR HEAT TREATING SHEET A ND TIN PLATE BARS.

APPLICATION FILED APR-.10, 1920- 1g41fiy0120 Patented May 23,: 1922.

3 SHEETS-SHEET I.

T. V. ALLIS, DECD. H. E. G. Mus. ADNINESTRATRIX- APPLICATION FILED APR-10,1920. 1A1? ,012 te May 23, 1922.

3 SNEETS-SHEET 2.

Frag. 3.

THOMAS I/TALLIS, MENTOR.

nJTTORJVZE' T. V. AL-LlS, DEC D.

. 1+. E. e. ALLIS, ADMINISTRATRIX. METHOD OF AND FURNACE FOR HEAT TREATING SHEET AND N PLATE BARS APPLICATION FILED APR. 10, I920. 1,417 1 Patented May 23,1922;

3 SHEET$-SHEET 3.

villa/0101"",-lurlllllrlunnv'w THOMAS VALLISZ 11v E TOR.

.ATTDRNEI? wthepair furnace shownin Figure 4.

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METHOD or AND-FURNAUE son nnnr-rnnnmn'e snnnrnu'n TI1\'I'-;PLATE Baas.

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Application filed April n,

T all 10710772 may concern. l 1 l Be it known that THOMAS Vn-Anms late a citizen of the United States, deceased, late of Pittsburgm'in the county ofAllegheny and State of Pennsylvania, invented certain new and useful Improvements inMethods of andl urnaces for Heat-Treating Sheet and Tin-Plate Bars, of which the following is a specification; r i 1 The present invention relates to the art of heat-treating sheet and tinplate bars, and bears a certain relation to an application for patent entitled Method of heat-treating sheet and tin-plate bars, Serial Number desirability of havi'ng-non-oxidized surfaces into sheets. a 5 l v The present invention illustrated in the accompanyingdrawings forming part of this specification, by its use in connection with a depressed temperature equalizing bar-pit (of which two types of same are shown), where the sheet and tinplate bars on the barspreparatory to rollingthe metal are soaked in the central part of the furon line 2-2 of Figure i.

nacelwhere the said bar-pit is locatedpn account of thisreglon of the furnace having l the most constant and equable temperature),

until all the bars are in a uniformly heated condition suitable for rolling down into sheets. l I

i In the drawings; Figure 1 is a longitudinal central vertical. section on line1-1 of Figure 2 is a transverse vertical section Figure 3 is a transvei: on line 3-Bof Figure 4. a a

Figure 41-. is a horizontal section of the pair furnace shown'in Figure 1, taken on line vertical section awe of Figure 1.

Figure 5 is a transverse verticalsection of aimodifiedformof hearth, for the furnace shown in Figure 4;, takenon linel-5 of Figure 6. r f

Figure 6 is aplan vlew of Figure 5;

The constructional features of the fur;- nace shown in Figures 1 to t iIlClIlSlVQWlll Specificatioiiof Iiettei'sP-atent. ll a tfillifid MTEIW 23, 1922.

1920. Serial Nd. $72,981:.

first be described. i The numeral 1 indicates a pair furnace, having a heating chamber 2,an d:.alnidgewall 3, pierced by a cutaway portion 4,-having a preferably rounded :top surface 5. The hearth 6 has formed therein several depressions or, pits 7 8, 9 for purposes described below. The depression or banpit 8 has preferably a saddle-back or hlp shaped bottomlO of metal or refractory material, adapted to support a series of piled sheet or tinplate bars 11. The saddlehaclr 10 is beveled transversely as seen in Figure 2,and also sloped rearwardly toward the interior of the furnace as shown iniig'ureqli iThe wallsof the bar-pit 8, being of refractory material are protected from theffwear of the edges of thebars ll,

bylmeansofupright gage bars 12, 12 etc.

which alsoghold the bars invertical align ment, when stacked or a gaged against same. -A metal cross-bar 1.3 extendsacross the bar-pit 8, for the purpose of holding the upright gage bars 14, 14: in position. It is seenthat on account of the transverse bevel, and the rearward slope of the saddleback 1.0, that the metal bars range themselves practically automatically againstthe gage bars l2 and 14;, gravity assisting in i the operation of gaging the bars with their longitudinal and vertical edges (both on the rear and on the side of the bars) in perfect alignment without any protruding edges or surfacesbeingexposed to the action of the furnace heat; The purpose of the even piling ais tofavoid uneven heating, or oXidized surfaces as before mentioned herein. The depression 9 is a continuation of the bar-pit 8, but has its bottomsurface preferably curved as shown in Figure 1 at 15. The underlying idea being that as the heated gases come from firebox 16, they pass over the. lire-wall through-the cutaway portion l, strike against the roof and front wall of the furnace at points; say 17, 18 approximately, and then deflect downwardly, passing through the depressions 8' and 9, and reverherate continuously, in the direction of annelongatedball or oval in direction between thelfire wall and the front wall of the furnace, thus serving to give the bars piled in the bar-pit 8 the benefit of this constantlyymaintained high and equabletemheatedinaterial. As set forth in the before i mentioned application, Serial Number 21 1,2 70, when the bars are piled near the side walls 19 of th furnace 1, as in some types of furnaces, t-hey become subject to serious wall drafts due to the proximity of the brick walls, and other poorly understood but well-known causes, and hence the location of the soaking pit 8 is placed in the center of the furnace in; the present invention, where a more even and constant heat is maintained at all times, and where thebars 11 receive the reverberatory action of-the burning gases as above described, The depression 7 is of substantially the same width as pit 8, with a slightly flared mouth as seen in Figure 4, so that the bars 11 can be readily manipulated and withdrawn from the furnace. I

On the hearth 6 are the skid castings 20, 20 which are adapted to support sheet and tinplate bars 21, 22 etc. in an inclined; position resting on one edge and a side with their edges 1n approximately vertical and longitudinal alignment. It is seen that gravity assists the bars 21', 22 etc, as in the case of the bars 11 ,to gage themselves against the faces 23, 23 etc. of the castings 20, 20.

- The furnace 1 is alsoprovided with down- Figure :3.

take fiues 2 1, 25, connecting passages 26, 27, 28, and a stack flue 29 to carry off the waste gases of combustion in the usual fashion.

In the F igures 5 and 6 of the drawings, I have shown a modified form or type of hearth which is adapted. to displace the one shown in Figure 1, and in which it is seen from said Figures 5 and 6 that the hearth skid castings 20, 20 are replaced by 30, 30 which are similar, and the saddle-baok 10 by the piling. rack 31. The castings 30, 30

are placed on an inclined: surface 3 1, while the rack 31 remains on a horizontal depressed surface in a transverse direction as seen in The piling rack 31 comprises a vertically disposed member 32, and; two oppositely projecting members 33, 33, as clear- 1y illustrated in Figures 5 and 6, forpiling the bars 35 with their longitudinal. and vertical edges in alignment. The use of the modified arrangement of hearth. skids and piling rack will be described below.

In. carrying out: my invention in the first described type of. furnace, I proceed asfollows. The bars are charged through the small doors 36, 37 etc., which expose only a small; portion ofthe opening. 38 at any one time, so as not to disturb theheat conditions on thehearth skids20, 20, two pairs of'bars usually being associated and handled: as: a

unit when placing them on the skids. After the bars are nitially heated on the hearth skids, they are removed one or more pairs at a time, by lifting them manually with a pair of tongs inserted in the longitrulinul grooves 39 of the hearth skids, and placed on the saddle-back 10 in the bar-pit R. in forming the piles on the saddle-back It), an outer pile of bars 2i, i. e. a pile nearer the doors 36, 37, etc, and inner pile 22. i. c. a pile nearer the fire wall 3, are successively superimposed upon each other in alternate relation on the saddle-back. The reason for this procedure is that the, inner piles of bars 22 positioned on the skids 20, in the interior of the heating chamber 2. are exposed to a more intense heat than the outer piles 21, and when they are piled alternately on the saddle-back 10, the temperature of the whole mass of bars is equalized. The hotter bars radiate the heat to those of lower temperature, and the latter readily absorb the heat so radiated according to a well understood physical principle, and thus a mass of bars of a uniform caloric condition is produced. Further it is seen that the even piling of the bars 11, on the saddle-back It) with their longitudinal, side and end edges in perfect alignment prevents all oxidation of the surfaces of the bars and undesirable scale is reduced to a negligible minimum. After the bars have been soaked or treated sufliciently in the bai pit 8. they are withdrawn as needed through doors 36, 37 and reduced by rolling in a Hill] into sheets of the proper gage.

The method adopted with the type oi lur nace shown in Figures 5 and 6 is substantially the same as that just described. but it is evident that the transference of bars from the skids 30, to the piling rack 3 l is accou'iplishcd much easier than the first described method. due to the relative nearness of the bars in the two positions, i. e. on the skids 20. and on the piling rack 31.

that I claim is:

1. The method of heating sheet and tinplate bars, which consists in piling them intoa mass with their side, longitiulinal and end edges in alignment, in the center of u furnace hearth, and heat-treatingsaid mass to obtain uniformly heated bars.

2. The method of heat-treating sheet and tinplate bars. which consists in piling them in a bar-pit in the center of a furnace. with all their edges in substantial vertical and longitudinal alignment, and heat-treating the mass of bars while so positioned. to produce bars of a uniform caloric condition.

3. The method of heat-treating sheet and tinplate bars to uniformly soften and minimize their oxidation, which consists in initially, heating them in primary piles on a. furnace hearth, transferring and arranging said piles-against a gagein a bar-pit formed 50 and end edges of a pile of bars deposited 1,417,012 p p v tilt below the general level of the furnace hearth,

and then completing the heat-treatment while the bars are in said bar-pit.

4;. The method of heat-treating sheet and tinplate bars which consists in initially heating them in primary piles, transferring and arranging said piles to formsecondary piles in a centrally disposed. bar-pit to form piles composed of alternate layers of bars taken from piles of varying comparative temperatures, and completing the heat-treatment while thebars are disposed in the said barpit with their vertical and longitudinal edges in alignment.

The method of heat-treatingsheet and.

tinplate bars, which consists in initially heating them in primary piles, transferring and arranging said: piles against a gaging means in a bar-pit, to form secondary piles composed of alternate layers ofbars of dil? .ferent comparative temperatures, and then completing the heat-treatment while thebars remain in the secondary piles with their side.

1 end and longitudinal edges in alignment.

. 6. A pair furnace hearth having a pair of horizontally disposed longitudinal portions for heating bars, and a. longitudinal clepressed bar-pit provided with means for aligning the longitudinal and end vertical edges of a pile of bars for homogenously heat treating same.

7. A pair furnace hearth having means i for heating sheet bars and a depressed barpit, provided with means for aligning the longitudinal, side and end edges of a pile of bars deposited therein for soaking purposes. 8. A pair furnace hearth having means for heating sheet bars and a depressed barposes.

1 edges ofa pile of sheet bars deposited therepit provided with means for aligning the longitudinal and vertical edges. of a p1le of bars deposited therein for heat treating pur- 9. A pair furnace hearth provided with a bar-pit,having a saddle-back bottom adapted to longitudinally and vertically align the in for uniformly heating said bars.

10. A pair furnace hearth provided with a bar pit, having a saddle-backbottom, and means for aligning the longitudinal, side therein for heattreating purposes.

11. A pair furnace hearth provided with i a bar-pit having a transversely beveled and longitudinally sloped. saddle-back bottom,

. and means for aligning the longitudinal,

and vertical. edges of a pile of bars deposited on said saddle back. p

12. A. pair furnace har-pit having a transversely beveled and longitudinally sloped saddle-back bottom, and means for aligning the longitudinal, side and rear vertical edges of a pile of bars deposited therein.

13. A pair furnace bar pit having a saddle-back bottom, and a plurality of gage bars in the sidewalls of said bar-pit, a cross bar extending across the bar-pit, and a number of gage-bars engaging the cross-bar and the bottomof the bar-pit for aligning the rear vertical edges of a pile of bars piled within the bar pit.

14:. In a pair furnace having a hearth, a firewall provided with a centrally disposed cut-away portion, a longitudinal central barpit below the general level. of the furnace hearth, and means in said bar-pit for gaging a pile of sheet bars with. their edges in longitudinal and vertical alignment.

15.. In a pair furnace, a fire wall having a centrally dispose-d cut-away portion, a pair of hearth skid castings, each adapted to hold a series of sheet bars with their longitudinal and vertical edges in alignment, a centrally positioned bar-pit between the hearth skid castings, and below the general level of the furnace hearth, provided with means for aligning the edges of a pile of sheet bars placed in the bar-pit.

16. In a pair furnace, a pair of hearth f skid castings, and a bar-pit below the general level of the said castings, and provided with means for aligning a pile of bars with all their edges in vertical and longitudinal alignment.

17 The method of heat-treating sheet and tinplate bars, which consists in initially heating them in primary piles on the in- Admiiiistmtrim of the estate of T homers V.

Allis, deceased.

Witnesses:

.VVILLIAM A. .EIrRrLri, DAVID S'roNEoIrHER. 

